标签: android-sqlite

我有很多方法在大部分内容遵循相同的算法,理想情况下我希望能够调用一个消除大量代码重复的泛型方法.

我有很多类似下面的方法,我最好希望能够只调用 Save<SQLiteLocation>(itemToSave);但是我有很多麻烦,因为这些方法 SQLiteConnection.Find<T>不会接受像泛型中的T这样的抽象数据类型.

有没有办法解决这个问题,如果我能解决这个问题,我会节省多达150行代码

这是我的代码:

    public bool SaveLocation(ILocation location, ref int primaryKey)
    {
        var dbConn = new SQLiteConnection (dbPath);

        SQLiteLocation itemToSave = new SQLiteLocation ();
        itemToSave.LocationName = location.LocationName;
        itemToSave.Latitude = location.Latitude;
        itemToSave.Longitude = location.Longitude;
        itemToSave.PrimaryKey = location.PrimaryKey;

  ----------------------------------------------------------------------------------------

        SQLiteLocation storedLocation = dbConn.Find<SQLiteLocation>
                                        (x => x.PrimaryKey == location.PrimaryKey);

        if (storedLocation != null)
        {
            dbConn.Update(itemToSave);
            return true;
        }

        else if (storedLocation == null)
        {
            dbConn.Insert(itemToSave);
            primaryKey = itemToSave.PrimaryKey;
            return true;
        }
        return false;
    }

在这里另一种方法看看我的虚线下面的两种方法中的代码基本上是一样的

    public bool SaveInvitation(IInvitation invitation, …

我正面临一个与SQLiteDatabase申请有关的问题.应用程序没有崩溃.这是我在Logcat中收到的日志.

 D/SQLiteDatabase:dispose database false
            java.lang.Throwable: stacktrace
            at android.database.sqlite.SQLiteDatabase.dispose(SQLiteDatabase.java:286)
            at android.database.sqlite.SQLiteDatabase.onAllReferencesReleased(SQLiteDatabase.java:280)
            at android.database.sqlite.SQLiteClosable.releaseReference(SQLiteClosable.java:74)
            at android.database.sqlite.SQLiteClosable.close(SQLiteClosable.java:106)
            at com.demo.model.SQLiteManager.close(SQLiteManager.java:74)
            at com.demo.ui.ContactFragment$ContactListAdapter.fetchContactData(ContactFragment.java:295)
            at com.demo.ui.ContactFragment$ContactListAdapter.<init>(ContactFragment.java:336)
            at com.demo.ui.ContactFragment$4.onQueryTextChange(ContactFragment.java:224)
            at android.support.v7.widget.SearchView.onTextChanged(SearchView.java:1150)
            at android.support.v7.widget.SearchView.access$2000(SearchView.java:103)
            at android.support.v7.widget.SearchView$12.onTextChanged(SearchView.java:1680)
            at android.widget.TextView.sendOnTextChanged(TextView.java:8340)
            at android.widget.TextView.setText(TextView.java:4413)
            at android.widget.TextView.setText(TextView.java:4252)
            at android.widget.EditText.setText(EditText.java:90)
            at android.widget.TextView.setText(TextView.java:4227)
            at android.support.v7.widget.SearchView.setQuery(SearchView.java:585)
            at com.demo.ui.ContactFragment.onPause(ContactFragment.java:153)
            at android.support.v4.app.Fragment.performPause(Fragment.java:2139)
            at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1117)
            at android.support.v4.app.FragmentManagerImpl.detachFragment(FragmentManager.java:1408)
            at android.support.v4.app.BackStackRecord.run(BackStackRecord.java:727)
            at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1617)
            at android.support.v4.app.FragmentManagerImpl.executePendingTransactions(FragmentManager.java:570)
            at android.support.v4.app.FragmentPagerAdapter.finishUpdate(FragmentPagerAdapter.java:141)
            at android.support.v4.view.ViewPager.populate(ViewPager.java:1177)
            at android.support.v4.view.ViewPager.populate(ViewPager.java:1025)
            at android.support.v4.view.ViewPager$3.run(ViewPager.java:254)
            at android.view.Choreographer$CallbackRecord.run(Choreographer.java:912)
            at android.view.Choreographer.doCallbacks(Choreographer.java:714)
            at android.view.Choreographer.doFrame(Choreographer.java:646)
            at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:898)
            at android.os.Handler.handleCallback(Handler.java:815)
            at android.os.Handler.dispatchMessage(Handler.java:104)
            at android.os.Looper.loop(Looper.java:207)
            at android.app.ActivityThread.main(ActivityThread.java:5769) …

我正在开发一个Android应用程序,它使用介绍幻灯片的材质介绍依赖项,但当幻灯片完成并尝试从幻灯片(MaterialintroActivity)切换到我的主要活动时,应用程序崩溃.

logcat的

 07-26 12:42:19.566 897-944/com.naive.LISTY E/Surface: getSlotFromBufferLocked: unknown buffer: 0xa9fb8d90

AppManifest代码

<application
    android:allowBackup="true"
    android:icon="@mipmap/icon"
    android:label="@string/app_name"
    android:supportsRtl="true"
    android:theme="@style/AppTheme">
    <activity android:name=".MainIntroActivity">
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />
            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>
    <activity android:name=".MainActivity"/>
</application>

MainIntroActivity

public class MainIntroActivity extends IntroActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {

    setFullscreen(true);
    super.onCreate(savedInstanceState);

    addSlide(new SimpleSlide.Builder()
            .title(R.string.title)
            .description(R.string.description)
            .image(R.mipmap.ic_launcher)
            .background(R.color.background)
            .backgroundDark(R.color.background_dark)
            .buttonCtaClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v)
                {
                    Intent main=new Intent(MainIntroActivity.this, MainActivity.class);
                    startActivity(main);
                }
            })
            .build());
}}

MainActivity代码

public class MainActivity extends AppCompatActivity { …

我最近为我的应用程序发布了一个更新，并且我收到一些用户的反馈，称他们的数据丢失了。经过分析，我确定我使用的单个内容提供程序始终返回一个空游标。

我没有更改内容提供者本身的代码或查询它的代码。数据格式没有改变。该问题仅在少数设备上可见，并且似乎仅限于Android 6.0（主要是三星，但也包括某些LG设备）。不仅会丢失初始数据，而且所有后续插入操作也不会持久化。

可以通过全新安装应用（删除+安装）解决此问题。

有谁知道如何解决/解决方法？

我认为这无关紧要，但这是代码：

Cursor cursor = contentResolver.query(Columns.contentUri(), Columns.ALARM_QUERY_COLUMNS, null, null, Columns.DEFAULT_SORT_ORDER);

List<AlarmActiveRecord> alarms = new ArrayList<AlarmActiveRecord>();
try {
    if (cursor.moveToFirst()) {
        do {
            alarms.add(factory.create(cursor));
        } while (cursor.moveToNext());
    }
} finally {
    cursor.close();
}
return alarms;

和内容提供者：

@Override
public Cursor query(Uri url, String[] projectionIn, String selection, String[] selectionArgs, String sort) {
    SQLiteQueryBuilder qb = new SQLiteQueryBuilder();

    // Generate the body of the query
    Preconditions.checkArgument(sURLMatcher.match(url) == ALARMS, "Invalid URL %s", url);
    qb.setTables("alarms");

    SQLiteDatabase db = …

我正在开发一个必须使用两个数据库的应用程序。我想将新数据库表中的记录添加到旧数据库表中，我已将新数据库放在项目的资产文件夹中，并且可以使用新数据库和旧数据库进行查询。

问题是当我尝试在方法上将新数据库附加到旧数据库时，发生了无法在事务中附加数据库的onUpgrade()错误。

public class DatabaseHelper extends SQLiteOpenHelper {
Context context;
SQLiteDatabase sourceDatabase;
private String TAG = this.getClass().getSimpleName();

private static final String DATABASE_NAME = "namesdemo_db";
private static final String SOURCE_DB_NAME = "namesdemo_db_s";
private static final int DATABASE_VERSION = 23;

private String DATABASE_PATH;
File dbFile;

// TABLE NAMES
private static final String TABLE_EMPLOYEE = "employee";
private static final String TABLE_FAVORITE = "fevorite";

// KEYS of Table Employee
private static final String KEY_ID …